A 37-year-old Redding man was sentenced Friday to 15 years to life in prison after pleading guilty in January to second-degree murder in a 2016 head-on traffic wreck that killed an 81-year-old Shingletown woman.

"I am truly sorry," said Matthew David Castaneda before he was sentenced. "I made a terrible mistake."

Castaneda took a plea bargain that guaranteed a 15-year-to-life prison term. He also won't be allowed to drive for the rest of his life if released from prison. He also pledged Friday to be an anti-drunk driving advocate.

He was driving a 2006 Chevrolet Malibu westbound in the eastbound lane on Highway 44 near Skylight Ridge while passing traffic around 2:40 p.m., on Aug. 3, 2016.

The California Highway Patrol said Castaneda tried to swerve back into his lane when he saw a 2012 Mini Cooper approaching in the opposite direction.

He lost control and collided with the car driven by Ellen B. Berblinger, 73, also of Shingletown.

Berblinger suffered major injuries in the wreck, while Evelyn Edith Blake, her close friend and passenger, died 10 days later at Mercy Medical Center.

"She was an extraordinary spirit," Berblinger said at the sentencing. "I remember this accident every day."

Castaneda’s blood alcohol level was 0.11 percent about two hours after the collision, prosecutors said. The legal driving limit is 0.08 percent.

He also admitted to recently taking multiple controlled substances, including methamphetamine, marijuana and hydrocodone, confirmed present in his blood sample.

A witness said Castaneda was driving his car to purchase drugs at the time of the collision, the DA's Office has said.

In addition to second-degree murder, Castaneda also pleaded guilty to driving under the influence of drugs and alcohol causing injury with a prior DUI conviction. Additionally, he admitted to a great bodily injury enhancement .

Castaneda, who is married and has a young daughter, has a prior conviction for an alcohol-related reckless driving offense from 2008 in Shasta County, as well as a prior conviction for driving under the influence of alcohol in Reno, Nevada, from 2014.

“I’m going to prison for life,” Castaneda reportedly told a CHP officer as he laid on a gurney in the emergency room at Mercy Medical Center after the Aug. 3, 2016, crash. “If I killed somebody I deserve to do time.”